To better understand the spectrum of adult acute myeloid leukaemia (AML) associated with core binding factor (CBF) translocations, 370 patients with newly diagnosed CBF-associated AML were analysed. Patients' age ranged from 16-83 years (median 39 years) with a slight male predominance (55%); 53% had inv(16); 47% had t(8;21). Patients with t(8;21) tended to be younger (P = 0.056), have lower peripheral blood white cell counts (P < 0.0001) and were more likely to have additional cytogenetic abnormalities (P < 0.0001). Loss of sex chromosome, del(9q) and complex abnormalities were more common among patients with t(8;21), while +22 and +21 were more common with inv(16). Overall, 87% [95% confidence interval (CI) 83-90%] of patients achieved complete response (CR) with no difference between t(8;21) and inv(16); however, the CR rate was lower in older patients due to increased resistant disease and early deaths. Ten-year overall survival (OS) was 44% (95% CI 39-50%) and, in multivariate analysis, was shorter with increasing age (P < 0.0001), increased peripheral blast percentage (P = 0.0006), in patients with complex cytogenetic abnormalities in addition to the CBF translocation (P = 0.021), and in patients with t(8;21) (P = 0.025). OS was superior in patients who received regimens with high-dose cytarabine, a combination of fludarabine and intermediate-dose cytarabine, or haematopoietic cell transplantation.